In the Andes, new evidence of climate change

Faster rate of warming than global average led Queen’s researchers to lakes in Ecuadorian National park.

Queen’s scientists published a study earlier this month that shows new evidence of climate change in tropical Andean lakes.

Neal Michelutti, lead author and a senior research scientist at Queen’s Paleoecological Environmental Assessment and Research Lab (PEARL), and John Smol, co-author, Queen’s biology professor and the Canada Research Chair in Environmental Change, travelled to Ecuador to examine three lakes in Cajas National Park.

The research, published on Feb. 3 in the journal PLOS ONE, presents data collected in the summer of 2011 and looks primarily at “diatoms” — a common form of algae.

Michelutti and Smol were part of a team that also included Alexander Wolfe from the University of Alberta, Colin Cooke from the Government of Alberta, William Hobbs from the Washington State Department of Ecology and Mathias Vuille from the University at Albany, State University of New York.

One of the biggest challenges in ecological or environmental work, Smol said, is the absence of direct measurement for long-term data, particularly in remote areas.

Collecting mud from the bottom of the lake is one way to overcome this, he added, as sediment contains fossils of organisms that once lived in the lake, for example.

“And if that mud’s not disturbed — and we have ways of determining if it’s disturbed — it’s like a history book or a museum, if you like,” Smol said.

“If you can remove that history book, it’s full of information.”

The research team pushed tubes into the lake, before matching the samples, or “cores” to historical time periods using radioisotopes.

“We section [the cores] into typically half centimetre or sometimes even finer intervals — the deeper you go, the older it’ll be,” he said.

“So we can say, this is about the 1850s, this is about 1910, this is about 1980s in the core.”

Smol said a large change in the lakes’ fossils was found to coincide with timing thought to be associated with global warming. While similar changes have been observed in other places, like Ontario, he said it was interesting to see these changes occur in “highly remote, highly sensitive lakes”.

“Basically greenhouse warming doesn’t have a passport — it goes wherever it goes,” Smol said.

Read the full story in the Queen’s Journal.